- Women either must be 1 year post-menopausal, surgically sterile, or if they are of child-bearing potential they must have been using systemic birth control, IUD or Norplant for at least 28 days prior to treatment start, or used barrier methods consistently at least 14 days before study gel administration, had a normal menstrual cycle for the month prior to the start of treatment, have a negative urine pregnancy test result upon entry into the study and agree to use a medically accepted form of birth control throughout the study period.